Steroids and related studies. Part XXVII. Tetrazoles from progesterone and 7-oxocholest-5-en-3β-yl acetate

Abstract

Progesterone when treated with an excess of hydrazoic acid in the presence of boron trifluoride gives a complex mixture from which two pure components have been separated and shown to be 17β-acetamido-3-aza-A-homoandrost-4a-eno[3,4-d]tetrazole (2) and 17β-(5-methyltetrazol-1-yl)-3-aza-A-homoandrost-4a-eno[3,4-d]tetrazole (4). The u.v., i.r., and n.m.r. spectra corresponding to the 3-aza-A-homo-4a-eno[3,4-d]tetrazole system of several steroid analogues have been examined. 7-Oxocholest-5-en-3β-yl acetate yielded 7a-aza-B-homocholest-5-eno[7a,7-d]tetrazol-3β-yl acetate (8). Hydrolysis of the ester function of the latter proceeds with allylic shift in basic medium, whereas acid hydrolysis does not show any such change. On Oppenauer oxidation both hydrolysis products give 7a-aza-B-homocholest-4-eno[7a,7-d]tetrazol-3-one.